IR Transmitter and Receiver pair can be easily made using 555 Timer, IR LED and TSOP1738 IR Receiver. This can be used for remote controls, burglar alarms etc. TSOP1738 is a very commonly used IR receiver for PCM remote control systems. It has only 3 pins, Vcc, GND and Output. It can be powered usin...

An Astable Multivibrator is an oscillator circuit that continuously produces rectangular wave without the aid of external triggering. So Astable Multivibrator is also known as Free Running Multivibrator. I have already posted about Astable Multivibrator using Transistors . Astable Multivibrator usin...

An Astable Multivibrator or a Free Running Multivibrator is the multivibrator which has no stable states. Its output oscillates continuously between its two unstable states without the aid of external triggering. The time period of each states are determined by Resistor Capacitor ( RC ) time constan...

We all know that a transistor has 4 regions of operation, in which Active, Cutoff and Saturation are commonly used. A transistor works in active region when worked as an Amplifier. When a transistor works as a Switch it works in Cutoff and Saturation Regions. In the Cutoff State both Emitter Base Ju...

TSOP17XX is a commonly used IR receiver for Infrared PCM remote control systems. It is used in TVs, DVD Players, Burglar Alarms etc. This component is built with PIN Diode, Preamplifier and internal filter for PCM (Pulse Code Modulation) frequency and its epoxy package is designed as an IR filter. T...

In communication systems, Frequency Modulation (FM) is the process in which information (message signal) is transmitted over a carrier wave by varying its instantaneous frequency. The difference between instantaneous frequency and central frequency of the carrier will be directly proportional to the...

In applications like Motor Speed Control, LED Brightness Control we may want to vary voltage given to it. Most often we use a variable resistor for that. The main problem with this control is the power dissipation across the variable resistor. This problem can be avoided by using All about Pulse wid...

Monostable Multivibrator is also known as One Short Multivibrator. As its name indicates it has one stable state and it switches to unstable state for a predetermined time period T when it is triggered. The time period T is determined by the RC time constant in the circuit. Monostable mode of 555 Ti...

The 555 Timer is the one of the most versatile linear hybrid Integrated Circuit (IC) which is used in variety of pulse generation, timer and oscillator applications. In 1972, Signetics Corporation first introduced this device as the SE/NE 555. 1.jpg Now a days it is manufactured by many companies in...

This tutorial is meant for beginners in the field of Atmel AVR programming. I hope that you already read my first tutorial How to blink LED using Atmega32 microcontroller . In most of the embedded electronic projects you may want to use a push button switch to give user inputs to the microcontroller...